diff --git a/default.nix b/default.nix
index 3b4f9f2..2e174a8 100644
--- a/default.nix
+++ b/default.nix
@@ -15,6 +15,58 @@ let
   unity_test_with_color = pkgs.unity-test.overrideAttrs {
     env.NIX_CFLAGS_COMPILE = "-DUNITY_OUTPUT_COLOR=1"; 
   }; 
+  libcello_debug = pkgs.libcello.overrideAttrs (prevAttrs: {
+    separateDebugInfo = true;
+    postInstall = ''
+         mkdir -p $out/lib/pkgconfig
+         cat >$out/lib/pkgconfig/libcello.pc <<EOF
+         prefix=$out
+         exec_prefix=\''${prefix}
+         libdir=$out/lib
+         includedir=$out/include
+
+         Name: ${prevAttrs.pname}
+         Version: ${prevAttrs.version}
+         Description: ${prevAttrs.meta.description}
+         Libs: -L\''${libdir} -lCello
+         Cflags: -I\''${includedir}
+         EOF
+    '';
+  });
+  packcc_main = pkgs.packcc.overrideAttrs (prevAttrs: {
+    version = "3.0.0";
+    src = fetchFromGitHub {
+      owner = "arithy";
+      repo = "packcc";
+      rev = "main";
+      hash = "sha256-oE9rdZmEEd8op5jkAzqEyD5rcZatn3IKIIJiQhGsqoc=";
+    };
+
+    nativeBuildInputs = [
+      pkgs.cmake
+      pkgs.gnumake
+    ];
+    
+    preBuild = ''
+      echo using ${if stdenv.cc.isGNU then
+         "gcc"
+      else if stdenv.cc.isClang then
+         "clang"
+      else
+        throw "Unknown compiler"
+    }
+    '';
+
+    buildPhase = ''
+       cmake $src -DCMAKE_INSTALL_PREFIX=$out
+       cmake --build .
+    '';
+
+    installPhase = ''
+       cmake --install .
+    '';
+    
+  });
   uem = callPackage ./pkgs/u/uem/package.nix {
     pkgs = pkgs;
   };
@@ -29,4 +81,6 @@ in
   unity_test_with_color = unity_test_with_color;
   uem = uem;
   cetcd = cetcd;
+  libcello_debug = libcello_debug;
+  packcc = packcc_main;
 }